A continuous time delta-sigma modulator has advantages such as anti-aliasing and high signal to noise ratio (SNR) characteristics. Due to such characteristics, the continuous time delta-sigma modulator is widely used in a wireless communication system such as 3rd generation partnership project (3GPP), long term evolution (LTE) or worldwide interoperability for microwave access (WIMAX).
With the recent enhancement in a semiconductor manufacturing technology, various researches on a delta-sigma modulator that reduces power consumption are being conducted. As an example, a multi-order delta-sigma modulator decreasing the power consumption of the entire circuit by using a multi-order loop filter (LF) is being provided, unlike a typical configuration in which an integrator increases as the order of the delta-signal modulator increases. In order for the multi-order LF to normally operate, the transfer function (TF) of the multi-order LF should satisfy a specific condition. In order to satisfy such a condition, there is a need to control the characteristics of elements (e.g., resistance or capacitance) in the multi-order LF. However, since the characteristics of the elements vary due to a process, voltage, and temperature (PVT) variation in a manufacturing process, there is a limitation in controlling the characteristics of elements in order to satisfy the operational condition of the multi-order LF. In order to satisfy the operational condition of the multi-order LF, the control range of the characteristics of the elements may also increase.